Mr. Wilson-- yes, it does have the desuperheater. My old unit, which was a custom-made one-off thing, also had a full condensing coil in addition to the desuperheater, so it had the capability of doing nothing but make hot water. I decided not to go for that additional option on the Water Furnace, but to stick with the desuperheater.
I'll admit it was very nice to know that, during A/C, house heat was being put directly into the DHW system, but it did add another level of complexity. Further, due to the nature of the system, refrigerant condensing temp in the winter was actually less than you'd normally keep your hot water at, so the unit would constantly go back & forth between hot water and house heat and never shut off: After getting water temp up to 125 or so, as soon as house heat was called for heat from the hot water tank would migrate through the desuperheater loop to the cooler refrigerant; as soon as house heat was satisfied, water temp had dropped..... and so on.
My solution was to set DHW t-stat as low as it would go (85+/-). The desuperheater, during the heating season, would keep the tank right around 90. When I wanted showers, laundry, etc., I just turned on the upper element in the water heater. Only took about 15 minutes to bring it up to 125. I'll do the same with the new one. As Whistlepig pointed out, the desuperheater really does work. As the unit I purchased already has a built-in circulator pump for the desuperheater I had to pull my old one, so you might be all set in that regard. Otherwise, it's just a matter of hooking up a loop to your existing water heater. I used the bottom drain and the hole from the lower element for my loop. You may notice that I also oversized both the expansion tank and the water heater- both are 80-gallon.
Yes, I run the return open like that; I had originally planned to duct it, but then realized that it was great for air circulation, not just for the house but also for the basement. Really cuts down on moisture build-up --and sometimes condensation-- on the cellar walls & in the corners, and allowed me to pull warm air from the basement from the woodstove to augment heat during really cold periods. I also have a whole-house heat recovery ventilator that brings fresh, warmed outside air into the basement, which is also picked up by the heat pump air intake. (Man, that's a lot of "also"s!)
This is my first TDI, the first NEW car I've ever bought for myself (wife gets the new ones...
), and my second diesel- had an 82 Peugeot 504D wagon for a few years. I became convinced of the desirability of diesel quite a few years ago; even once investigated replacing the 307 V8 in my 72 Blazer with a diesel-- and was told it wasn't possible; the truck would shake itself apart... this was obviously before diesel in light trucks & cars caught on in the US, back in 1975 or so....
Mine's an 05 with the PD engine. Only has 65K on it now, but gets similar mileage- on a road trip, if the A/C's not on, it'll do 50 (with A/C 45-48); around town about 42-45. Good for around 850 miles on a full tank.:thumbsup: Love that!
